This invention relates to a process for increasing the coefficient of friction of textile fabrics and to products produced by the said process.
As is known in the art, it is desirable for parts of certain garments to have a relatively high coefficient of friction, for example the waistbands of trousers and elasticated corsetry.
These parts are usually processed narrow fabrics and are generally known as textile grippers. The grippers ensure that the garment will not move readily relative to the surface therebeneath which may be another garment or a persons skin.
Generally, the coefficient of friction is increased by coating the fabric with a material of relatively high coefficient of friction. However, such a coating must adhere perfectly to the fabric in question. It must be medically safe, inert to perspiration and have the ability to accommodate distortions and movements of the garment to which it is attached, without cracking and/or separating therefrom. In addition, it must retain these characteristics after repeated washing or dry cleaning.
There have bee many publications of prior art techniques for producing grippers. The formulations used for increasing the coefficient of friction include organic rubbers and then various derived compounds, either synthetic or natural. Silicone rubbers of the polydimethyl siloxane type in which benzoyl peroxide is the curing agent and reacts to form methyl side groups have also been used.
All these types of grippers require temperatures to be elevated above 71.degree.C to bring about the required cure.
To obtain the required gripping action either the whole face of a fabric or a substantial part of said face had to be processed, thereby yielding a composite fabric. Application techniques include spreading, dipping, spraying, calendering and kiss roll in normal atmospheric conditions, curing being achieved by heated chambers or ovens.
Grippers produced by these methods have some or all of the following disadvantages.
1. High modulus to obtain required force in normal direction to obtain sufficient grip. This means that the garment is restrictive.
2. Adhesion of rubber to fabric is obtained by impregnation of base fabric and the weave must give a key to the rubber. This process disfigures the face of lace and therefore cannot be used on corsetry.
3. These types of rubbers will not withstand dry cleaning with tetrachlorethylene or perchlorethylene.
4. Pin holes are a constant problem as the release of gases are an inherent part of the curing process.
5. These types of rubbers are not medically inert and cannot be worn next to the skin.
6. As previously stated to obtain sufficient grip large areas have to be coated so that the resultant product is heavy and cumbersome.